Expansion joint for roadways



p 1941- R. c. OLMSTED I I 2,255,599

EXPANSION JOINT FOR ROADWAYS Filed March 17, 1958 2 Sheets-Sheet 2 05554; 6. OLMSTEO.

1 N VE NTOR.

ATTORNEYS.

Patented Sept. 9, 1941 I 2,255,599 EXPANSION JOINT FOR RoAnwA'Ys Russell Crolmsted, Nor-wood, N. J.

Application March 17, 1938, Serial No. 1'96,35l

4 Claims.

This invention relates to new and useful improvements in'roadways and similar passageways and more particularly it pertains to a new and novel construction of expansion joint therefor.

' Roadways, driveways and similar passageways, especially when constructed from concrete, arev formed in sections commonly called slabs. In the building of such roadways, it is the practice to leave a space between the adjacent edges of the several slabs, which space is filled with a suitable packing material intended to. excludethe elements from the joint. This packing material is generally of a compressible nature which will permit of expansion of the ,slabs and a consequent compressing of the packing material without resulting injury to the slabs.

One object of the present invention is to'improve the construction of roadway joints and to render such joints more effective for the purpose intended.

Another object of the invention is to provide a new and novel construction of dowel bar and support therefor, which will permit of relative linear movement of the slabs of a cement road way and yet, prevent relative vertical movementthercof.

A feature of the present invention resides in a novel construction and arrangement of parts whereby the structure is maintained rigidly in a set-up position which the structure will maintain during the pouring or forming ofjthe slabs of the roadway.

A further feature of the invention resides in a novel construction which will permit of the ready assembly of the structure upon the subgrade at the location where the roadway is being formed.

Still another, feature of the invention resides in a construction and arrangement of parts which permits of a choice of pro-formed packing or sealing elements, or sealing means of the poured type.

Other features of the invention relate to certain novel and improved construction, arrangements and combinations of parts hereinafter dethe accompanying drawings illustrating the invention in its preferred forms and the following detailed description'of the constructions therein illustrated. v

In the drawings: Figure 1 is a fragmentary sectional view of a roadway illustrating the device of the present invention in elevation,

Figure 2 is a vertical sectional view taken sub stantially on the line 22 ofFigure 1,

Figure 3 is a view similar to Figure 2 taken substantially on-the line'3-3 of Figure 1,

,Figure 4 is a detail vertical sectional view of one of the dowel .bar supporting trackways and guides,

Figure 5 is a vertical detail sectional view taken substantially on the line 5-5'of Figure 1, Figure 6 is a distended perspective view illustrating a portion of the invention,

Figure 7 is a detail perspective view illustrating a modified form of the invention,

Figure 8 is a fragmentary sectional view of a roadway illustrating the modified form of Figure 7 in position therein,

Figure 9 is a view in elevation illustrating an element employed in the modified form of the invention,

Figure 10 is a fragmentary sectional view showing the modified form of the invention in longitudinal section, and;

Figure 11 is a detail perspective view.

Referring to! the drawings, and particularly; to Figures 1 through 6 thereof, the reference numeral I5 designates'the sub-grade of the roadway, I6 and ll designating slabs of the roadway proper. Interposed between the adjacent edges of the slabs is a supporting packing material B, to be hereinafter more specifically described.

In carrying out the invention, I employ dowel bars l8 and while I have herein. shown these dowel bars as being of I-beam construction, "it isto be understood that dowel bars of other crosssectional shapes, such for example as bulbbeams or the like, may be employed. I prefer, however, to use dowel bars of standard forms in order to maintain an economical construction.

In carrying out the present invention, I place along the roadway, supporting members I9 which in the present instance are shown as of angle- 1 iron construction. These supporting members are placed in pairs with the members in each pair in parallelism and spaced from each other in such a manner as to occupy positions upon opposite sides of a joint between slabs, when the roadway is formed.

2| and a right angularportion 22 extending normally substantially parallel with the top surface of the sub-grade l5, but spacedtherefrom. These dowel bar supporting trackways are 1 secured to the support l9 by means of bolts 23 which pass through the vertical wall 24 of the supportsv I 9 and through the; vertical portion 2| of the dowel bar. supporting'trackway, as best i illustrated in Figures 1 andB, v In securing the dowel bar supporting track- -'ways to the supports [9, asabove described, they throughout the entire length of the channel ar jarranged in pairs, and by positioning one,

trackwayofeach pair upon each: side of thefin- The dowel bars l8 pass through two opposed channel members 25. As best illustrated in Fig-, 1 ureld, each of these channel members comprises a main body portion 26, side flanges 21' and flanges 28 extending at right angles to the side flanges 21. Furthermore, each of these chan nels is-provided, in its vertical portion 26 with a plurality-ofsuitably spaced openings 30, through which the dowel bars pass, the shape of which openings is determined by the cross-sectional shape of the dowel bars employed.

It ls'to be understood-that the channel members 25 are'provided with an opening 30 to receive each of he dowelbars, regardless of the number of dowel bars employed and that in the assembly of the structure the dowel bars pass through these openings and form a temporary support for the channel members 25.

.The reference numeral 3| designates an upper packingstrip and 32 designates a lower packing strip. These packing strips 3| and 32 are formed I from any suitable material and as best illustrated in Figure 6, they are clamped between the adjacent flanges 28 of the channel members 25,

i by rods or similar elements 40. The flanges 28 are preferably provided with openings 33, ex-

tending therethrough to provide for gripping the packings as they are clamped between their respective flanges 28.

' The lower packing'strip 32 is, as shown in the drawings, of a width which extends from the lower. edge of the channel members to the top surface of the sub-grade IS, the upper packing beingiof such width that its upper edge will be substantially flush with the top surface of theslabs or finished roadway, this construction and I arrangement of parts being clearly illustrated in Figures 2 and 3.

The rods 40, heretofore mentioned as securing the channel members together, extend through the channel members and into the slabs as illustrated at 4| in Figure 5 of the drawings. Inter-'- mediate of its ends, each of the rods 40 is weakened as indicated at 42 in the drawings to providefor rupturingof th bars between the channel members upon relative movement of the slabs, thus leavingv the channel members free for I 4 independent movement while the extension 4| of the rods 40, dormmeans for bonding the channel members to their respective slabs.

The channel members 25 are secured together in opposed relation and this arrangement prohed jointyand thetrackways in each-pair in longitudinal alinernent with each other, in such manner that in the'assembling of the parts, a I dowel :bar may 1 besupport'edby each .pair of iv trackways, and, have slidable 'engagement with, one of said trackways.

members and is of such'cross-sectional dimensions as to be placed under considerable com .pression when the channel members are drawn up to position to clamp the packing strips 3| and 32 as heretofore described. The packing element 5| will be provided with suitablyshaped openings to permit of the passage therethrough of -the dowel bars l8 and the rods in assembling the several parts in their operative position.

While I have herein described the several packing elements 3|, 32 and 5| as being of the preformed type, it is to be understood that the invention is not to be limited to use of packings of this type since other packings, such for example as those of the plastic, semi-plastic or poured type may also be employed. For example, when poured packings are employed, the

' and the several parts are retained in this asstruction of the roadway.

' As illustrated in Figure 5, the rods 40 are in the form of threaded bolts and the channel members 25 are shown as clamped between nuts or the like 43 and 44 with the weakened portions 42 of th rods positioned'in the chamber 50 between the opposed channel members.

As best illustrated in Figure 6, the trackways are provided with crimped-over portions 35 which pass around the edges of the lower flanges of the dowelbars. I8 while the other trackway of each pair is not so formed, the dowel bars merely resting upon said last mentioned trackway of each pair. The reference numeral 36 designates a cap plate which is placed upon the upper flange of the dowel bar and has its side edges crimped as at 31 to embrace theside edges of the upper flange of the dowel bar. The reference numeral 38 designates a shield, which may be formed of any suitable material of which paper or light metal may be cited as good examples. As illustrated in Figure '4, this shield conformsto theshape of the sides of the dowel bar I8 and is secured in position by the crimped portions 35 and 31 respectively, of the supportmg trackway and cap plate 36. However, it is to be understood that the crlmpings 35 will not in any way interfere with the free sliding move-- ment of the dowel bar relatively to the trackway.

The cap plate 36 has .a right angular end 38 which extends downwardly around the outer end of the dowel bar l8 and a filler block 39 is positioned in the outer end of the cap plate 36 upon each side of the dowel bar.

By reference to Figure 3, it will be apparent that this construction provides a housing D, in

bar, which is designated E in said Figure 3, is not so protected and will. therefore, be securely bonded to, or anchored in the concrete, forming the slab in which this one} of the dowel bar is positioned.

In forming my Joint for roadways, the dowel bars will be positioned, as above described. However, the housings D, in one of which one end of each of the dowel bars will be positioned, will be arranged upon opposite sides of the joint in alternate pairs of supporting trackways. In

. other words, in one pair of supporting trackways,'the housing Dwill be upon one side of the joint, whil in each of the next adjacent pairs of trackways, the housings D will be upon the opposite side of the joint.

By this construction, each of the dowel bars will be anchored to a slab on one side of the joint, while its other end will be freely movable or slidable in the slab upon the opposite side of the joint.

In practice, the structure is set up in either of the heretofore described manners, the angleirons l9 and packing strip 32 forming the means by which the structure is supported upon the subgrade. set-up position, the concrete forming the slabs l6 and I1 is poured, completely enclosing the structure in the roadway, as illustrated in Figures 2 and 3 of the drawings. As the material of the slabs sets, the entire structure will be bonded to the slabs except of course one end of each dowel bar which of course will be free to slide in the housing in which it is enclosed.

With the parts in the position just described, immediately upon relative movement of the slabs either from expansion or contraction, the rods will part at their weakened portions 42, whereupon, the slabs will be free to move relatively to one another under temperature variations during which movements, the dowel bars will move with the respective slabs to which they are bonded with their other ends freely movable relatively to the slab in which they are positioned.

In addition to forming means for supporting and guiding the sliding movements of the dowel 1 bars during movements of the slabs, these trackways and the housings which enclose the freely movable ends of the dowel bars, provide wear surfaces for the movable ends of the dowel bars,

thus preventing wearing away of slabs as a result of the sliding movement between the free ends of the dowel bars and the slabs in which they are positioned.

In Figure '7, I have illustrated a modified form of the invention in which the channel members 25 and 26 are not employed.

In said Figure '7, the dowel bar is designated and is illustrated as of I-beam form. One end of the dowel bar 60 is enclosed in a housing which the other end is exposed to be enclosed in the concrete which forms the adjacent slab in order that the dowel bar may be anchored to this slab. By this construction, one end of each dowel bar is anchored in or bonded to one slab at one end,

With the parts of the structure in their a shield which may be formed from paper, light metal or the like and it is to be understood that there will be one of said shields upon eachside of the dowel bar 80. These shields conform in shape to the sides of the dowel bar and as in the heretofore described form of the invention, extend along the inner faces of the flanges of the dowel bar. The lower flange of the dowel bar rests upon a channel member 64, the side flanges of which extend upwardly around the edges of the lower flanges of the dowel bar. This channel forms a trackway upon which the free end of the dowel bar may slide and also provides a wear surface upon which the dowel bar slides, thus preventing wear or damage to the slab.

Filler blocks 66 are employed at the end of the dowel bar, there being one of said filler blocks upon each side of the dowel bar as in the heretofore described form of the invention.

The cap plate 6], the channel track member 64, the shields and the filler block are all held in their assembled position, by straps or the like 61.

Two of these strapsv 61 are passed around the assembly and after they have been placed in posibedded in the next adjacent slab.

It, is, of course, to be understood that the housings which enclose the ends of the dowel bars will be staggered or positioned in such a manner that alternate dowel bars will have their housings and bonded ends in the same slabs.

In Figures 8 and 9, I have illustrated a slightly modified form of the invention, which differs only from the form shown in Figures 1 through 6, in

that in lieu of the channel members 25 and 26, I

employ plates 10 which may be either. strip of sufiicient length to extend throughout the length of the joint, or may be washer-like members II of the type illustratedin Figure 9 0f the drawings.

In this form of the invention, I employ a lower packing strip 12 and an upper packing strip 13, or a packing strip of a single width extending from the sub-grade l5, to the surface of the finisl ed roadway, may be employed. In either construction, the packing strip is formed with openings through which the dowel bars pass and'the plates 10 or the washer-like members ll effectively preventing bonding together of the slabs when the concrete is poured to form the slabs. This is true, since the'plates 10 or wastre -like members II have openings I2 therein which are of a shape and size, snugly to fit the ,dowel bar yet without offering any resistance to its movement therethrough.

In Figures 10 and 11, I have illustrated still another modified form of the invention in which ,washer-like plates are employed, which washerlike plates are in the form of integral extensions of the trackways-upon which the dowel bars are supported.

,The trackways are designated 80, in these figures and in the form of the invention illustrated in Figures 1 to 6 of the drawings, they comprise a channel shaped member bent as at 8| to provide a vertical portion 82 and a horizontal portion 83. These trackways are "supported upon the subgrade I5 by angle bars IS in the manner heretoiore'described and as illustrated in Figure of 3 the drawings.

Upon the tree end'of each trackway, there is 3 a plate 84 in the form ofan integral extension of the trackway and said plates are provided 1 with openings 85 therethrough which correspond in shape to the cross-sectional shape of the dowel 1 bar in connection with which they are employed.

of each is mounted within a housing in the manner heretofore described to permit of said end having, free sliding movement in the slab in which it is mounted.

From the foregoing it is apparent that the present invention provides a new and novel roadway joint structure which is, by its own structure, maintained in a practically rigid unit until a such time as the roadway has been completed or at least poured, after which, as a result of expansiori or contraction of the slabs, the structure becomes two separate elements each carried by its-respective slab and at the same time I eifectively dividing the roadway into a plurality of slabs, each capable of movement independently of the others.

Furthermore, the invention provides a structure in which wear plates are provided" for the movable ends of the dowel bars, thus preventing wearing away of the concrete of the slabs by reason of direct contact of the dowel bars with the walls of the recesses in the slabs in which they are mounted.

The invention also provides a novel construction and arrangement of parts which permits of the use of dowel bars of various standard. crosssectional forms other than circular, the type generally employed in structures of this type.

While the invention has been herein illustrated in its preferred forms, it is to be understood that it is not limited to the specific constructions herein set forth andthat it might be carried out in such other forms as rightfully fall within the scope of the appended claims.

Having thus described the invention, what is claimed as new is:

1. An expansion joint structure comprising in combination, a pair of angle irons extending along the roadway sub-grade in spaced parallel relation to each other, dowel bar supporting tra'ckways carried by each of said angle irons with each trackway of one angle iron in longitudinal alinement with a trackway of the other angle iron, adowel bar supported upon each two alined trackways, means cooperating with one of the trackways supporting eachdowel bar for enclosing one end of the dowel bar carried thereby and opposed channel members supported upon said dowel bars intermediate of the inner ends of the trackways, said opposed channel members having alined openings for a shape corresponding to the cross-sectional form of the dowel bars to receive the dowel bars and cooperate therewith to form a seal for the space between the opposed channel members.

2. A housing for enclosing the end of a dowel bar in the building of roadways, said housing supportedv upon the trackway, shields extending.

between the trackway and the cap-plate, and means for retaining said trackway and said capplate in operative position upon a dowel bar supported .upon the trackway, said means embracing the entire assembly adjacent the opposite ends thereof.

4. A housing for enclosing the end of adowel bar in the building of roadways. said housing comprising in combination, a trackway for sup-- porting a dowel bar, a cap-plate for a dowel bar supported upon the trackway, shields extending between the trackway and the cap-plate, and meansfor retaining said trackway, and said capplate in operative position upon a dowel bar sup-- ported upon the trackway, said means comprising straps embracing the entire assembly and distorted into engagement with the shields.

. RUSSELL C. OLMSTED. 

